AP BIOLOGY

Detailed explanation-1: -Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.

Detailed explanation-2: -Bronchioles end in tiny air sacs called alveoli, where the exchange of oxygen and carbon dioxide actually takes place.

Detailed explanation-3: -The alveoli are surrounded by tiny blood vessels, called capillaries. The alveoli and capillaries both have very thin walls, which allow the oxygen to pass from the alveoli to the blood.

Detailed explanation-4: -During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs. This happens in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.

Detailed explanation-5: -Pulmonary ventilation provides air to the alveoli for this gas exchange process. At the respiratory membrane, where the alveolar and capillary walls meet, gases move across the membranes, with oxygen entering the bloodstream and carbon dioxide exiting.